How Should Running Shoes Fit, According to an Expert

How to fit running shoes

Verywell / Amelia Manley

The proper running gear can make a significant difference in your training and running results. From apparel that keeps you chafe-free to shoes that provide the right amount of cushioning and stave off blistering, proper gear should work to improve the running experience—allowing you to remain as injury-free and safe as possible.

To find the best fitting running shoes, educating yourself on shoe characteristics can help you invest in the right pair. Before you begin shopping, though, check out these running experts' tips on what to look for in shoe fit.

How Running Shoes Should Fit

Every runner has different needs when it comes to running shoes. In fact, everyone has different foot shapes, running goals, training efforts, and gait. That said, certain characteristics in shoe fit are universal. Here is what you need to know about the fit of your running shoes.

Overall Shape

The width and shape of the shoe should match your foot. To test this, remove the foot bed inside the shoe and stand on it to verify the width and shape are similar to your foot. If your foot is bigger than the foot bed, you may need a wider shoe otherwise, this shoe could cause blistering.

Top of the Foot

When trying on a shoe, first notice how the top of your foot makes contact with the top material of the shoe. Ask yourself if it feels comfortable or if it feels tight or restrictive. Too little movement along the top of the foot could become an issue.

“Some shoes have a lot of structure in that upper material for support or protection, which can make the shoe restrictive or cause pain,” says Matt Scarfo, NASM CPT-OPT, CES, PES, FNS, of Precision Nutrition Pn1 and a running coach.

Midfoot Fit

For the best cushioning effects, look for thick midsoles. They can reduce shock when you impact the ground.

When you try on a pair of running shoes, try running so that you can test the cushioning when you strike. Some running stores allow you to take a short run to try out the shoes before you invest while others encourage you to jog around the store. Ask if you can run a little in the shoe first.

Toe Fit

When you put the shoe on, test this amount of space you have with your thumb. According to Peter F. Lovato, DPM, FACFAS, a northern Illinois foot and ankle specialist, you should have one thumb breadth from the top of the toe to the edge of the shoe.

Make sure your toes do not get bunched up in the shoe, which can lead to injuries. You also want to make sure your feet have room to swell when running.

Heel Fit

To check for fit, Timothy Woods, CCC, GMU, a fitness and nutrition specialist, lift your heel as you hold the back of the running shoe. Ideally, your running shoe should feel snug around your heel but leave some wiggle-room for your toes.

If your heel is slipping, one of two issues could be at play. First, the shoe could be too big if your heel moves around, which can be annoying and cause blisters. A second possible reason for a slipping heel is that you do not have your shoes laced properly.

Make sure you are using the eyelet on the shoe to ensure a snug fit on your shoe. If your heel still slips, the shoe is likely too big.

Signs Your Running Shoes Are the Wrong Size

If you experience pain, injuries, or frequent blisters consistently when running, these issues could be related to the fit and size of your running shoe. Try not to ignore or run through any of these problems but instead interpret them as a signal that you may need another shoe size or a different type of shoe. Here are some common indicators that your running shoes might be the wrong size.

Plantar Fasciitis

Plantar fasciitis is a common injury among runners, sometimes associated with how hard you pound the ground as you strike. Thin midsoles can also contribute to this issue in some cases.

According to the Journal of Sports Science and Medicine, softer or thicker midsoles can provide significant cushioning and reduce plantar vibrations as you touchdown. If you try thicker midsoles and you still have plantar fasciitis, you should speak with a healthcare provider about your symptoms.

Foot Structure

Lovato recommends that if you have any foot structure issues or deformities, such as bunions or tailor’s bunions, go up in size and width. Doing so, can help prevent aggravating your condition as well as reduce or prevent pain and discomfort.

“The fit [of your running shoe] should be snug, but not too snug,” suggests Lovato.

Another indicator that you may need a different size shoe, are signs of focal redness on your foot after a run. This could indicate that the shoe is too tight or rubbing in the wrong place.

Black Toenails

Black toenails can sometimes occur in long-distance runners due to improper footwear and heavy pounding. To mitigate this issue, Nick Winder, founder of Illness to Ultra and a UESCA ultra running coach suggests trying to wiggle your toes slightly to determine if you have the appropriate foot motion and activation in the shoe.


While your feet may naturally expand a little when you are running, too much swelling can be caused by friction from your shoes. If this occurs frequently when you run, you may need a different size shoe.

“You need around a 1/2-inch space between your toes and the end of the shoe to allow for foot swelling and forward foot motion in the shoe on descent,” says Winder.

However, if you have persistent swelling after exercise, you may want to talk to a healthcare provider. There could be another explanation for the frequent swelling you are experiencing.

A Word from Verywell

Ensuring you have the right running shoe is imperative for training, as this can help you avoid short- and long-term injuries. You should take your time when shopping and not simply purchase a pair of shoes based on style or name brand.

Likewise, a healthcare professional such as a podiatrist or orthopedist can provide information and guidance on how to select the right running shoe for you. This is especially true if you have any lingering injuries that disrupt your ability to train. In these situations, you might need more guidance on the best type and size of shoe for you, especially if you have orthotics.

Frequently Asked Questions

  • How much room should you have in a running shoe?

    You need room in the shoe to avoid injuries, such as blistering, black toenails, and painful friction. Experts recommend having approximately 1/2 inch of space between your toes and the end of the shoe to allow for any forward foot motion and swelling.

  • Are shoes supposed to be tight at first?

    Shoes do not need to be tight at first. Instead, you should be able to slightly wiggle your toes to ensure you have the correct foot motion. That said, the shoe should be tight enough not to slip, but loose enough to allow movement. Walk or run around the store and notice if your foot slips out of the shoe. If it does, move on to another pair.

  • Is it OK if running shoes are a little big?

    Running shoes should run a little big. Use your thumb as a guide. Ideally, you should have a thumb’s width from the top of the toe to the edge of the shoe for extra space. That said, they should not be slipping off your feet. You also can check to see how you have tied your running shoes to ensure they are secure.

3 Sources
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Sun X, Lam WK, Zhang X, Wang J, Fu W. Systematic review of the role of footwear constructions in running biomechanics: implications for running-related injury and performanceJ Sports Sci Med. 2020;19(1):20-37 PMID:32132824

  3. Sun X, Lam WK, Zhang X, Wang J, Fu W. Systematic review of the role of footwear constructions in running biomechanics: implications for running-related injury and performanceJ Sports Sci Med. 2020;19(1):20-37. PMID:32132824

By Jennifer Purdie, M.Ed, CPT
Jennifer Purdie, M.Ed, is a certified personal trainer, freelance writer, and author of "Growth Mindset for Athletes, Coaches and Trainers."